Browsing by Author "Syu, Yu-Ying"

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A quasi-planar thin film field emission diode
(2007-11-01)
Lin, Kao-Chao
;
Juan, Chuan-Ping
;
Lai, Rui-Ling
;
Chen, Hsia-Wei
;
Syu, Yu-Ying
A novel quasi-planar thin-film field emitter is fabricated by thin-film deposition and wet etching processes. The spacing between the emitters and collectors could be well controlled on the basis of the thicknesses of Cr thin films, which create submicron gaps. A forming process increases emitter surface roughness and results in a higher field enhancement factor, which shows better field emission characteristics. The turn-on voltage (at which the current level is 100 nA) of the device with a Cr thin film thickness of 300 nm is as low as 12 V, and the current fluctuation in I hour test at a driving voltage of 20 V represents a variation from -86 to +114%.
Growth and field emission characteristics of carbon nanotubes using Co/Cr/Al multilayer catalyst
(2007-07-01)
Cheng, Huang-Chung
;
Lin, Kao-Chao
;
Tai, Han-Chung
;
Juan, Chuan-Ping
;
Lai, Rui-Ling
A multilayer catalyst, Co/Cr/Al, was employed to synthesize carbon nanotubes (CNTs) at atmospheric pressure by thermal chemical vapor deposition (thermal CVD). The relative growth rates, calculated on the basis of the average lengths of nanotubes grown at different temperatures, were utilized to estimate an activation energy of 0.84eV for the multilayer catalyst. Such a low activation energy implies that the nucleation and growth of nanombes could be effectively enhanced via the multilayer catalyst due to the well-distributed small catalytic nanoparticles by Al supporting layer and higher activity by Cr co-catalyst layer. It was also found that nanotubes grown using this configuration at 500 degrees C exhibited excellent field emission characteristics, and showed a highly uniform emission image in a phosphor-coated anode plate.